For a motivation and discussion of these principles, we refer to [1]}, [2]}.
For a detailed explanation of why REF –REF  indeed naturally lead to REF –REF , we refer to [3]}, which also contains a small example that illustrates the use of our workhorse axiom REF .
More generally, that same reference [3]} also provides much more information about—and motivation for—the framework that we summarise here.
